I think it depends on how well your TV handles non native resolutions. Different types of TVs tend to do the job better than others. I have heard that LCD flat panels, and plasmas can be quite bad at it. This is just what I have gleaned from others posts, I don't have any personal experience with this yet.
With that said, I am considering an LCD TV purchase to replace my desktop monitor. This will be used to play games as well. The 1920x1080 res is way too high to play any current or future games at an acceptable frame rate. Thus the LCD TVs I'm looking at are going to have a lower native res. The trade off of course is that when and if we ever see 1080p content, the TV will not be able to display it in its full glory. I think in situations like this you have to look at what your main purpose for the TV is. You want high def, go 1080p. You want a replacement for your desktop monitor, perhaps a lower native res would be beneficial.
With that said, I am considering an LCD TV purchase to replace my desktop monitor. This will be used to play games as well. The 1920x1080 res is way too high to play any current or future games at an acceptable frame rate. Thus the LCD TVs I'm looking at are going to have a lower native res. The trade off of course is that when and if we ever see 1080p content, the TV will not be able to display it in its full glory. I think in situations like this you have to look at what your main purpose for the TV is. You want high def, go 1080p. You want a replacement for your desktop monitor, perhaps a lower native res would be beneficial.